@ Poster,
I'll speak for CCNA because i am groomed in that filled. You can have a boot camp training for one month (weekends only), just in case you work or are in school. This weekend training could be Fri-Sunday, that is 12 days, after you are done with that, it depends on your level of assimilation, in reading and understanding your configurations,(LAN, NAT). So give or take, you can utilize 3 to 4 months on self study, It is advisable you go for a practical training, so you could learn more on the routers and switches and how they are utilized and applied in Networking as a whole.
If you need more details, do send a mail to:
vanessa.m@torquetechnologies.net.
I had my training there and this lady will shed more light in the world of CCNA.
Till then, take care.